There are many types of congenital anomalies of the hand and usually they occur in a mixed pattern.The aetiology of these anomalies is not quite clear but mostly is a mutation caused by environmental factors during development of limb buds of the embryo.Development of limb buds start during the fourth intrauterine week, and maturation of parts occur proximo¬distally. Any lesion of the bud during maturation will result in necrosis and disappearance of either the whole limb or part of it resulting in an anomaly.Many methods of classification of congenital abnormalities of the hand were introduced, based on different principles either descriptive, topographical, embryological, or morphogenetic, but each of these classifications has disadvantages which make them difficult to be used.The most recent, accurate, and simple classification which was approved by all societies depends upon whether it is part of systemic disease or localized in the hand. These are either failure of formation, failure of differentiation, duplication, over-growth, under-growth, or congenital constriction band syndrome.